Film speed enhancement camera

ABSTRACT

A camera having a controlled internal light source for enhancing the speed and sensitivity of the film therein at the time of exposure. The light is below the level necessary for visual fogging but decreases the amount of image photons required to reach the threshold density of the film.

United States Patentv Cole m]- I 3,823,413 July 9, 1974 FILM SPEEDENHANCEMENT CAMERA [75] Inventor: MelroseR. Cole, Prides Crossing,

Mass.

[73] Assignee: C & C Research, Inc., Danvers,

Mass.

22 Filed: July17, 1972 Primary Examiner.lohn M. Horan Attorney, Agent,or FirmWeingarten, Maxham &

[21] Appl. No; 272,684 Schurgin 52 'us. Cl 95/1 R, 355/70, 355/133 [57]ABSTRACT [51] 1 Int. Cl. G03b 27/54 vA camera a ng a ntr lled internallight source for [58] Field of Search; 355/67, 68, 70; 96/27, enhancingthe speed and sensitivity of the film therein 96/452, 64 at the time ofexposure. The light is below the level 6 5 g necessary for visualfogging but decreases the amount [56 6 R fer nc Cit d of image photonsrequired to reach the threshold den- UNITED STATES PATENTS my l m1,840,351 1/1932 Douden .5. 355/133 X 18 Claims, 5 Drawing Figures I I Ii 1,1

PATENTEDJIIL 91 3,823,413

Fig. 2. i CPA d I CONTROL FILM SPEED ENHANCEMENT CAMERA FIELD .OF THEINVENTION This invention relates to photography and more specificallyconcerns a camera having an internal light source positioned in front ofthe film for providing speed enhancement of the film simultaneouslywithexposure while at the same time preserving the inherent imagequality of the film.

D scussion OF THE PRIOR ART It is well known that photographic filmshave definite predetermined sensitivities, often referred to as ASAspeed values. Films which are designed for some purposes are much moresensitive than others. However, every film has its characteristicthreshold of exposure value which must be reached before any image willappear onthe film when it is developed. More specifically, a certainlevel of radiant energy (normally photons oflight) must impinge upon thefilm in order to en ergize grains of silver halide sufficiently so thatthey are reduced to metallic silver upon development in order to obtaina visible exposure. Standard characteristic curves; density plottedagainst the logarithm of the exposure, indicate that for most films,after the threshold level of exposure is reached a substantial increasein exposure is normally necessary before any significant increase indensity is observed. This means that objects cannot normally bedistinguished on a film within this region 'of the curve.

It has been attempted through chemical means to increase the speed offilm and this has been successful to a certain limited degree. Since thedifferences between films having speeds of ASA and those having speedsof ASA 1000 are primarily chemical in nature, it is to be expected thatappropriate well known additional chemical treatment may enhance thesespeeds to some limited degree. However, these methods are short term andsomewhat uncontrolled while at the same time cause adverse chemicalreactions which may make the film discolor or fade at some later time.These methods also tend to reduce the image quality as compared to thenormally exposed and processed film. Attempts also have been made toincrease the effective speed 'of film through physical means such as byadmitting light from the subject being photographed to impinge upon thefilm; this light does not pass through the lens. Such a means isdescribed in U.S. Pat. No.. 3,577,898 wherein light is admitted throughopenings or by means of fiber optics located in positions around theperiphery of the lens.

Thedisadvantages of the chemical enhancement has already been pointedout. The physical method using ambient light emanting from the subjectalso has significant disadvantages. Ambient light admitted to the camerain this fashion floods the film and is uncontrolled. If the lightavailable is low the ambient light is also low. It may thus be seen thatthe supplemental exposure so provided is quite indefinite when suchphysical means are used.

SUMMARY OF THE INVENTION Broadly speaking. this invention comprises acontrolled light source within the camera which provides supplementallight to the film simultaneously with the primary exposure. In thismanner, the speed of the film is significantly increased so that minimallight which would otherwise be too low to cause animage to be formed onthe-film will be able to provide a visible exposure. This method ofproviding controlled supplemental light permits a decrease in the amontof image photons required to reach the threshold density of the film andmay be termed concurrent photon amplification or CPA. The resultingincrease in film speed is attained with no loss in image quality.

Through .the meansdisclosed herein it is has been demonstrated that byadding an amount of non-image light .which is just below the thresholdlevel of the film but concurrent with the image exposure, the totalcombined amount of CPA and image light now enables one to obtain animage that was previously unattainable.

Several different means'may be used for providing this CPA light, suchas the use of one or more controllable light sources, such as smallincandescent bulbs or light emitting diodes, or other visible orinvisible light sources. These are arranged in convenient locationsbetween the lens and the film. Another method is to use a light sourcetogether with a light'transmitting fiber having one side formed todiffuse the light toward the film. Alternatively a fiber optic bundlemay be used with the tips of the bundle arranged in a suitable fashionto direct the light toward the film. While this invention isparticularly adaptable to focal plane shuttered cameras, it is by nomeans limited to them and other shutter mechanisms or cameraarrangements may be accommodated.

This disclosure generally refers to CPA as light" but the inventionwould work equally well with other electromagnetic radiations whichprovide the desired fil excitation.

. BRIEF DESCRIPTION OF THE DRAWING The advantages, features and objectsof this invention will become more readily apparent from the followingdetailed description taken in conjunction with the accompanying drawingwherein:

FIG. I is a schematic sectional view of a focal plane shutter cameraconstructed in accordance with this invention;

FIG. 2 is .a typical characteristic curve showing both the controlandthe amplified curve for a particular film;

FIG. 3 is a plan view of a light enhancement structure and schematic ofthe circuit of the invention similar to that shown in FIG. ll;

FIG. 4 is an alternative embodiment of the light enhancement structureof FIG. 3; and

FIG. 5 is another alternative embodiment of the light enhancementstructure of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to thedrawing and more particularly to FIG. I thereof there is shown a camera10 having a lightrestrictive housing 11, a focal plane shutter 112, alens assembly 13, and a film 14 with supply and take-upspools IIS and16. The drawing only indicates the essential features of the camera inschematic fashion and is not intended to show the details of a workingdevice. This camera operates in the normal manner whereby shutter 112provides a slit which moves across the film for even exposure thereof.The shutter is normally closed so that no light is admitted to thesurface of the film.

This type of camera readily permits the lens to be removed and replaced,and provides easy access to the interior of the camera for mounting thelight means for this invention. Between lens 13 and shutter 12 isprovided light source 17 comprising a plurality of small incandescentbulbs 21, sometimes termed pin or grain-of-wheat bulbs, connectedelectrically through means of wires 22 to power supply 23. Tubes 20 aretypical feed-through deviceswhich may be used. This structure is shownschematically in FIG. 3 wherein powersupply 23 comprises switch 24 andbattery 25. The bulbs may be connected in parallel as shown in FIG. 1 orin series as shown in FIG. 3. Switch 24 is shown externally in FIG. l asa push button but it may be any desired type of switch. The power supplymay be included within the camera, attached externally or it may beentirely separate from the housing with appropriate electricalconnection to the light assembly.

Just prior to exposing the film, switch 24 is closed to energize bulbs21. This creates a low level of light within the camera but the film isnot exposed to this light since shutter 12 remains closed. When thepicture is taken and shutter 12 opens, the light rays from the subjectare focused onto the film through lens assembly 13 and at the same timethe low level light from light source 17 also'impinges upon the film.The photons of light provided byinternal light source are sufficient to,in effect, enable the film so that the additional light provided by thesubject, even though it may be at a very low level, will provide adetectable image.

In order to provide complete control of the light level provided bybulbs 21, a rheostat 26 may be included in the circuit. Thus, it ispossible to use a relatively wide range of light intensity for theconcurrent photon amplification provided by the light source and thelight level may be'present just prior to exposure, depending upon theconditions at the time. It is recognized that if the light level of thelight source is reduced to a certain point the light which they providecould change spectrally wherein an'appropriate filter should be insertedbetween the bulbs and the shutter. This could be provided in manydifferent ways but the specific structure is not important to theinvention here.

With reference now to FIG. 2 it may be seen how the film density isincreased with respect to the logarithm of exposure by concurrent photonamplification (CPA) as provided by this invention. The solid linelabelled CONTROL- is the normal characteristic curve for a particularfilm and it may be seen that from the threshold level at the left end ofthe line a relatively large increase in exposure is required before anychange in density occurs; Where the curve is nearly horizontal. it isnot possible to produce distinguishable exposures. n the other hand thebroken line labelled CPA shows that with the internal light provided bybulbs 21 substantially any change in exposure will cause a measurableincrease in density thereby permitting objects to be distinguished onthe film with the same exposure which previously would not create anyuseful image. Starting at the origin of the CPA line at the left, it maybe seen that the line slopes upward and is not substantially horizontalas is the CONTROL line. The speed of thefilm is thus significantlyincreased. It may be appreciated that this invention substantiallyincreases exposure latitude and creates a gradient which opens an en- 4tire range of the characteristic curve which without CPA is normally ofminimal or no use.

While the internal light source may be energized prior to exposure, itis noted that with the type of camera shown, the film is not exposed tothe additional light until the shutter is opened and the main exposureis made. The additional light photons thereby impinge upon the filmsimultaneously with light from the object being photographed, thusallowing a minimal amount of light from the subject to provide adevelopable image. It is assumed that without the added internal light,the minimal light from the subject would be insufficient to create animage.

It has been found that if the additional light is provided to the filmbefore the main exposure, the desired amplification effect is reduced.This is primarily be cause when light photons impinge upon the film,free electrons are generated within the silver halide. The higher levelof energy thus created dies out quite rapidly, the time normally rangingbetween one microsecond to one second. Likewise it has been found thatadding the internal light after the main exposure is not as satisfactoryas if it were done simultaneously. Thus for these and practical reasonsrelating to the physical structure and operation of the camera, it ispreferable that the internal light be added simultaneously with the mainexposure.

FIG. 4 shows a single fiber optic rod 27 formed in a circle andsubjected at its ends to light from bulb 31 connected in circuit 23. Theside of the rod facing rearwardly toward the film may be treated by somemethod such as grinding to cause the light supplied by bulb 21 todiffuse toward the film.

FIG. 5 shows another alternative embodiment whereby bulb 31 supplieslight to a fiber optic bundle 32. This bundle of fibers is split up andspread around in a circle 33 with the fiber ends directed rearwardlytoward the film, thereby providing light to the film for the purposes ofthis invention. All of the light source examples shown are arranged in acircle but such a configuration is not necessary and any arrangementwhich fits within the confines of the camera and provides the light tothe film is satisfactory.

Certain data has been gathered with regard to different films anddevelopers using the structure of this invention as described above. Thefollowing are examples of this data. Example No. l: Eastman Kodak Tri-X-Pan film developed with D-76 developer. Using an exposure time of1/200 of a second in a camera with a f/4.7 aperture and a 15 volt clearbulb energized at 8.2 volts for amplification, the film speed wasincreased from ASA 400 to ASA 1000. Example No. 2: Eastman Kodak HighSpeed Infrared No. 2481 film developed with D- 19 developer. Using aWratten 89B filter and an exposure time of U of a second in a camerawith an f/5.6 aperture and a 15 volt clear bulb energized at 6.5

volts'the film speed increased from ASA 40 to ASA.

125. With the same film, camera and filter set-up but with the CPA lightsource changed to a 15 volt green bulb energized at 8.2 volts, the filmspeed was increased from ASA 4O to ASA 160. Example No. 3: Eastman KodakPanatomic-X film developed with D-76 developer. Using an exposure timeof H40 of a second and a 15 volt clear bulb energized at 9.8 volts, thefilm speed changed from ASA 32 to ASA 64. Example No. 4: Eastman KodakNo. 2475 Recording film developed with DK-SO developer. Using anexposure time of 1/800 of a second in a camera with an f/8 aperture anda volt clear bulb energized at 7.8 volts, the film speed changed fromASA 1000 to ASA 3200. Using the same film and the camera setting butwith a 15 volt red bulb energized at 4.5 volts the film speed increasedfrom ASA 1000 to ASA 4000. Tests with Eastman Kodak Kodacolor X alsoshowed marked increases in film speed-The CPA light source will normallybe spaced from the film by l to 2 inches but light intensity may bevaried as necessary to permit such distances to be widely variable.

From the above examples it may be seen that a signif' icant improvementin film speed is provided by this invention. The scope of theseexamplesis sufficient to show that the invention operates as desired to provideresults which permit photography in light which is otherwise too dim tocreate an image on film. They also show that enhancement is provided forcolor film as well as for blackand white film. It may thus beappreciated that by using this invention, photographs may be madewithout additional light such as flash bulbs, photoflood bulbs andstrobe lights, in normal room illumination or even under somewhat darkerconditions.

The embodiment and variations specifically described above concern theinvention as applied to a focal plane shutter camera, but it is readilyapparent that this same invention can be used with any type of cameraincluding still and movie cameras, stereo, space and graphic artscameras and cameras used for special effects such as panoramic and widescreen movie photography. The primary requirement is that the additionallight be applied to the film substantially concurrently with exposure tothe subject. If a camera is used which has a shutter within the lensassembly, concurrent photon amplification may be provided with a secondshutter between the light source and the film which is synchronized withthe main camera shutter. Altematively, a switch which is synchronized tothe camera shutter may be provided to energize the light source at thesame time that the picture is being taken. This invention could beespecially advantageous for use in acrial cameras which have no shutterat all. These cameras time the film speed proportional to the speed ofthe aircraft so that the exposure aperture is constantly open. Whenavailable light is very low, CPA could make the difference betweenvaluable photographs and a wasted trip.

The light source envisioned as useful for this invention is not limitedto incandescent bulbs or any particular wavelength of electromagneticemission. Nor is the type of film to which this invention may be appliedlimited in any way. Benefits from CPA may be derived by color and blackand white films, negative or positive, movie or still, continuous timeor graphic arts, astronomical, visible, ultraviolet, X-ray,radiographic, re cording, infrared and films used in aerial and spacephotography. Further, even though it has been stressed that CPA isparticularly useful where the light from the subject is minimal, it hasother more far ranging uses. It may be used where light is sufficientfor a photograph but not sufficient for a fast shutter speed forstop-action photography or other specialefiects which may be desired.

The broad application of concurrent photon amplification to photographyand films in particular can be readily appreciated in view of theabove-description. It is likely that modifications and improvements willnow occur to those skilled in the art which arewithin the scope of thisinvention.

What is claimed is:

1. An improved camera comprising:

a light restrictive housing;

a lens assembly mounted in one side of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly;

a light source comprising a plurality of small lamps arranged withinsaid housing'betwecn said lens assembly and said film; and

means within said housing for subjecting said film to non-image lightfrom said light source substantially simultaneously with the. exposureof said film to image light from the subject being photographed, therebyenhancing the speed of said film while pre? serving its inherent imagequality.

2. The camera recited in claim 1 and further comprisa power supplyelectrically connected to said nonimage light source; and

a switch connected between said power supplyand said non-image lightsource.

3. The camera recited in claim 1 wherein said means for subjecting saidfilm to said source of non-image light comprises shutter means withinsaid camera.

4. The camera recited in claim 3 wherein said shutter means comprises afocal plane shutter.

5. The camera recited in claim 1 and further comprising means forcontrolling the intensity of said nonimage light to accommodatedifferent image light intensity levels and film density characteristics.

6. The camera recited in claim 1 wherein said means for subjecting saidfilm to light comprises a first shutter for exposing said film to imagelight and a second shutter for exposing said film to non-image light.

7. The camera recited in claim 6 wherein said first shutter is locatedwithin said lens assembly and said second shutter is located betweensaid light source and said film.

8. The camera recited in claim 1 wherein said means for subjecting saidfilm to light comprises a focal plane shutter.

9. An. improved camera comprising:

a light restrictive housing;

a lens assembly mounted in one side of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly;

a plurality of small lamps circularly arranged between said lensassembly and said film;

a focal plane shutter within said housing between said lamps and saidfilm;

a power supply electrically connected to said lamps;

and

a switch connecting between said power supply and said lamps;

. whereby said film is exposed to the light from said lamps and thesubject being photographed substantially simultaneously when saidshutter is opened.

10. The camera recited in claim 1 and further comprising means forcontrolling the duration of non-image light exposure to said filmindependently of the means 7 for exposing said film to said image light,providing that said film is exposed to said image light and saidnonimage lightsimultaneously.

11. An improved camera comprising; a light restrictive housing; a lensassembly mounted in one side of said housing;

means'for retaining photographic film within said 7 housing adjacent theother side thereof opposite said lens assembly;

an independentlyenergized, non-image source for providing light to thephotosensitive surface of said film, said non-image source for providinglight comprising a plurality of small lamps arranged within saidhousing; and means for subjecting said film to photons of nonimage lightfrom said source simultaneously with the exposure of said film to imagelight from the subject being photographed, said image light beingnormally below an intensity level sufficient to produce a developablevisible image on said film and said non-image light being below anintensity level sufficient to cause visible fogging of said film, the

simultaneous exposure of said film to said nonimage light together withsaid image light thereby changes the sensitometric characteristics ofsaid film and specifically enhances its speed while preserving theinherent image quality of said film so as to produce a developablevisible image of the subject being photographed.

12. The camera recited in claim 11 and further comprising means forcontrolling the intensity of said nonimag e light to accommodatedifferent image light intensity levels and film densitycharacteristics.

13. An improved camera comprising;

a light restrictive housing;

a lens assembly mounted in one side of said housing and providing theonly access for external light to the interior of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly;

a plurality of small lamps arranged between said lens assembly and saidfilm for providing non-image light of uniform intensity over thatportion of said film being exposed to image light, said plurality oflamps being energizable independently of the image light to which saidfilm is exposed;

a focal plane shutter within said housing between said lamps and saidfilm;

a power supply electrically connected to said lamps;

and

a switch connected between said power supply and said lamps;

whereby said film is exposed simultaneously to'both the light from saidlamps and from the subject being photographed when said shutter isopened.

14. An improved camera comprising:

a light restrictive housing;

a lens assembly mounted in one side of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly for recording an originalimage of a subject resulting from exposure of said photographic film toimage light from said subject through said lens assembly;

a separately actuable means including a plurality of small lampsarranged within said housing for providing distinct non-image light tosaid film simultaneously with the exposure of said film to image light,said image light passing through said lens assembly, said non-imagelight reaching said film directly and without passing through a lens andhaving an intensity level insufficient to cause visible fogging of saidfilm, thereby changing the sensitometric characteristics of said filmand specifically by enhancing its speed while preserving the inherentimage quality of said film.

15. An improved camera comprising:

a light restrictive housing;

a lens assembly mounted in one side of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly;

a light source comprising a plurality of small lamps arranged withinsaid housing between said lens assembly and said film; and

shutter means within said housing for subjecting said film to non-imagelight from said light source substantially simultaneously with theexposure of said film to image light from the subject beingphotographed, thereby enhancing the speed of said film while preservingthe inherent image quality of said film.

16. An improved camera comprising:

a light restrictive housing;

means for retaining photographic film within said housing adjacent oneside thereof for recording an original image of a subject resulting fromexposure of said photographic film to image light from said subject;

optical means mounted in another side of said housing for focusing animage'of a subject on the plane of said film;

an independently energized, non-image source for providing light to thephotosensitive surface of said film, said source for providing non-imagelight comprising a plurality of small lamps arranged within saidhousing; and

means for subjecting said film to non-image light from said sourcesimultaneously with the exposure of said film to image light from thesubject being photographed, said non-image light having an intensitylevel which is insufficient to cause visible fogging of said film,thereby changing the sensitometric characteristics of said film andspecifically by enhancing its speed while preserving the inherent imagequality of said film.

l7. Animproved camera comprising:

a light restrictive housing;

a lens assembly mounted in one side of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly;

a light source comprising a plurality of small lamps arranged withinsaid housing; and

means within said housing for subjecting said film to non-image lightfrom said light source substantially simultaneously with the exposure ofsaid film to image light from the subject being photographed,

thereby enhancing the speed of said film while preserving the inherentimage quality of said film.

18. An improved camera comprising:

a light restrictive housing;

a lens assembly mounted in one side of said housing;

means for retaining photographic film within said housing adjacent theother side thereof opposite said lens assembly;

a light source comprising a plurality of small lamps film.

1. An improved camera comprising: a light restrictive housing; a lensassembly mounted in one side of said housing; means for retainingphotographic film within said housing adjacent the other side thereofopposite said lens assembly; a light source comprising a plurality ofsmall lamps arranged within said housing between said lens assembly andsaid film; and means within said housing for subjecting said film tonon-image light from said light source substantially simultaneously withthe exposure of said film to image light from the subject beingphotographed, thereby enhancing the speed of said film while preservingits inherent image quality.
 2. The camera recited in claim 1 and furthercomprising: a power supply electrically connected to said non-imagelight source; and a switch connected between said power supply and saidnon-image light source.
 3. The camera recited in claim 1 wherein saidmeans for subjecting said film to said source of non-image lightcomprises shutter means within said camera.
 4. The camera recited inclaim 3 wherein said shutter means comprises a focal plane shutter. 5.The camera recited in claim 1 and further comprising means forcontrolling the intensity of said non-image light to accommodatedifferent image light intensity levels and film density characteristics.6. The camera recited in claim 1 wherein said means for subjecting saidfilm to light comprises a first shutter for exposing said film to imagelight and a second shutter for exposing said film to non-image light. 7.The camera recited in claim 6 wherein said first shutter is locatedwithin said lens assembly and said second shutter is located betweensaid liGht source and said film.
 8. The camera recited in claim 1wherein said means for subjecting said film to light comprises a focalplane shutter.
 9. An improved camera comprising: a light restrictivehousing; a lens assembly mounted in one side of said housing; means forretaining photographic film within said housing adjacent the other sidethereof opposite said lens assembly; a plurality of small lampscircularly arranged between said lens assembly and said film; a focalplane shutter within said housing between said lamps and said film; apower supply electrically connected to said lamps; and a switchconnecting between said power supply and said lamps; whereby said filmis exposed to the light from said lamps and the subject beingphotographed substantially simultaneously when said shutter is opened.10. The camera recited in claim 1 and further comprising means forcontrolling the duration of non-image light exposure to said filmindependently of the means for exposing said film to said image light,providing that said film is exposed to said image light and saidnon-image light simultaneously.
 11. An improved camera comprising: alight restrictive housing; a lens assembly mounted in one side of saidhousing; means for retaining photographic film within said housingadjacent the other side thereof opposite said lens assembly; anindependently energized, non-image source for providing light to thephotosensitive surface of said film, said non-image source for providinglight comprising a plurality of small lamps arranged within saidhousing; and means for subjecting said film to photons of non-imagelight from said source simultaneously with the exposure of said film toimage light from the subject being photographed, said image light beingnormally below an intensity level sufficient to produce a developablevisible image on said film and said non-image light being below anintensity level sufficient to cause visible fogging of said film, thesimultaneous exposure of said film to said non-image light together withsaid image light thereby changes the sensitometric characteristics ofsaid film and specifically enhances its speed while preserving theinherent image quality of said film so as to produce a developablevisible image of the subject being photographed.
 12. The camera recitedin claim 11 and further comprising means for controlling the intensityof said non-image light to accommodate different image light intensitylevels and film density characteristics.
 13. An improved cameracomprising: a light restrictive housing; a lens assembly mounted in oneside of said housing and providing the only access for external light tothe interior of said housing; means for retaining photographic filmwithin said housing adjacent the other side thereof opposite said lensassembly; a plurality of small lamps arranged between said lens assemblyand said film for providing non-image light of uniform intensity overthat portion of said film being exposed to image light, said pluralityof lamps being energizable independently of the image light to whichsaid film is exposed; a focal plane shutter within said housing betweensaid lamps and said film; a power supply electrically connected to saidlamps; and a switch connected between said power supply and said lamps;whereby said film is exposed simultaneously to both the light from saidlamps and from the subject being photographed when said shutter isopened.
 14. An improved camera comprising: a light restrictive housing;a lens assembly mounted in one side of said housing; means for retainingphotographic film within said housing adjacent the other side thereofopposite said lens assembly for recording an original image of a subjectresulting from exposure of said photographic film to image light fromsaid subject through said lens assembly; a separately actuable meansinclUding a plurality of small lamps arranged within said housing forproviding distinct non-image light to said film simultaneously with theexposure of said film to image light, said image light passing throughsaid lens assembly, said non-image light reaching said film directly andwithout passing through a lens and having an intensity levelinsufficient to cause visible fogging of said film, thereby changing thesensitometric characteristics of said film and specifically by enhancingits speed while preserving the inherent image quality of said film. 15.An improved camera comprising: a light restrictive housing; a lensassembly mounted in one side of said housing; means for retainingphotographic film within said housing adjacent the other side thereofopposite said lens assembly; a light source comprising a plurality ofsmall lamps arranged within said housing between said lens assembly andsaid film; and shutter means within said housing for subjecting saidfilm to non-image light from said light source substantiallysimultaneously with the exposure of said film to image light from thesubject being photographed, thereby enhancing the speed of said filmwhile preserving the inherent image quality of said film.
 16. Animproved camera comprising: a light restrictive housing; means forretaining photographic film within said housing adjacent one sidethereof for recording an original image of a subject resulting fromexposure of said photographic film to image light from said subject;optical means mounted in another side of said housing for focusing animage of a subject on the plane of said film; an independentlyenergized, non-image source for providing light to the photosensitivesurface of said film, said source for providing non-image lightcomprising a plurality of small lamps arranged within said housing; andmeans for subjecting said film to non-image light from said sourcesimultaneously with the exposure of said film to image light from thesubject being photographed, said non-image light having an intensitylevel which is insufficient to cause visible fogging of said film,thereby changing the sensitometric characteristics of said film andspecifically by enhancing its speed while preserving the inherent imagequality of said film.
 17. An improved camera comprising: a lightrestrictive housing; a lens assembly mounted in one side of saidhousing; means for retaining photographic film within said housingadjacent the other side thereof opposite said lens assembly; a lightsource comprising a plurality of small lamps arranged within saidhousing; and means within said housing for subjecting said film tonon-image light from said light source substantially simultaneously withthe exposure of said film to image light from the subject beingphotographed, thereby enhancing the speed of said film while preservingthe inherent image quality of said film.
 18. An improved cameracomprising: a light restrictive housing; a lens assembly mounted in oneside of said housing; means for retaining photographic film within saidhousing adjacent the other side thereof opposite said lens assembly; alight source comprising a plurality of small lamps arranged within saidhousing between said lens assembly and said film; and shutter meanswithin said housing for subjecting said film to non-image light fromsaid light source and to image light from the subject beingphotographed, thereby enhancing the speed of said film while preservingthe inherent image quality of said film.